The Odorant Receptor Recognizing Camphor in a Camphor Tree Specialist Orthaga achatina (Lepidoptera: Pyralidae)

Abstract

Camphor has been used as an effective repellent and pesticide to stored products for a long history, but Orthaga achatina (Lepidoptera: Pyralidae) has evolved to specifically feed on the camphor tree Cinnamomum camphora. However, the behavioral response of O. achatina to camphor and the molecular basis of camphor perception are totally unknown. Here, we demonstrated that both male and female adults were behaviorally attracted to camphor, suggesting the adaptation of O. achatina to and utilization of camphor as a signal of C. camphora. Second, in 40 O. achatina OR genes obtained by analyzing antenna transcriptomes, only OachOR16/Orco significantly responded to camphor in the Xenopus oocyte system. Finally, by molecular docking analysis and site-directed mutagenesis, the Ser209 residue is confirmed to be essential for binding of the oachOR16 with camphor. This study not only reveals the camphor-based host plant choice and olfactory mechanisms of O. achatina but also provides a molecular target for screening more potential insect repellents.

Female-Biased Odorant Receptor MmedOR48 in the Parasitoid Microplitis mediator Broadly Tunes to Plant Volatiles

“…Previous studies have demonstrated the importance of a single key residue, such as His83 of the SfruOR14 in the fall armyworm Spodoptera frugiperda, in biasing the receptor against certain ligands . Similarly, the Ser209 residue was found to be essential for the OachOR16 binding with camphor in Orthaga achatina . Interestingly, site-directed mutagenesis of the conserved His57 and Glu61 residues in the SfuOR47 and SlituOR49 in S.…”